I have been down the "mad mile" a couple of times during my time here in Bozeman, but it's always been at the end of the summer in low water - with a guide.  Well, rafting and kayaking enthusiasts are loving this time of year, when it's high water on the Gallatin River.  Check out this video of the guides from Wild West Rafting training on this mile.  YIKES, I think I'll stick to low water.  :)